Generally, the inventive technology relates to the formation of structures utilizing fill materials capable of hardening, such as concrete. Specifically, the inventive technology involves methods and apparatus for the formation of such structures utilizing enhanced load-bearing capabilities. The inventive technology may be particularly suited to the use of manufacturing and prefabrication processes in construction industry applications.
Modern building techniques may widely employ the use of poured concrete to form structures such as columns, walls, and other building features. One key to successfully using poured concrete in building applications may be to erect a formwork capable of forming the concrete to a desired shape before the concrete has a chance to harden. Conventional formworks may typically rely on panel systems to accomplish this kind of concrete formation. In these kinds of systems, panels may often be placed in parallel orientation to create a space between them into which concrete may be poured. In this manner, poured concrete may be formed within the boundaries of the panels. Further, multiple pairs of panels may frequently be linked together to create a particular shape desired for a given situation. For example, panels may be linked together to form columns, walls, rooms, and other kinds of structures used in building applications. After panels have been linked together in a desired configuration, concrete may be poured into the space between the panels, following which a period of time may be required for the concrete to harden. Once the concrete has hardened, a building structure may be considered to have been formed, and the panels may either be left in place or removed depending on the nature of the application.
However, conventional formworks and the techniques for using them may entail significant drawbacks. For example, conventional formworks may typically be required to be assembled at a job site. This may require performing such assembly in less than ideal conditions and using labor and tools set up at the job site for generalist tasks. Also required may be using building materials delivered to a job site in standardized configurations and adapting them at the job site for the particular needs of the job. For example, if a formwork panel length is not the correct length required for a particular placement, it may be necessary to cut the panel to the required dimensions. Such use of labor on an as-available basis and for on-site customization of materials may be costly and inefficient, requiring time and labor resources that otherwise could be committed elsewhere.
Another drawback may be that conventional formworks may not be able to support external loads before concrete has been poured and has hardened. Once concrete has been poured and has hardened, such a completed concrete structure frequently may be used to support and stabilize other construction elements. Examples of this may include support beams, floor joists, staircases, and the like, any of which may be routinely anchored to a completed concrete structure for support. Indeed, in many applications, a completed concrete structure may serve as a fundamental support for a building structure. However, prior to pouring concrete, it may be that conventional formworks do not possess sufficient strength in and of themselves to provide support for these kinds of construction elements. As a result, it may be necessary to wait until concrete has been poured and hardened, so that the resulting completed concrete structure may be used as a support element. This waiting period may create inefficiencies in the construction process, and sometimes may force the use of alternative methods and devices for support prior to pouring concrete. Moreover, the direct attachment to a conventional formwork of construction elements useful for servicing the formwork itself may be precluded, such as staircases, service platforms, and the like.
A further drawback may be that conventional formworks typically may have minimal ability to support themselves. It may be that conventional formworks often require external bracing to prop up the formwork, such as by kickers or other attached braces. In addition, conventional formworks may often require involved ancillary systems of scaffolding, platforms, ladders, hoists and other similar features to allow construction personnel to service the formworks. Because conventional formworks may typically have minimal ability to support themselves, these ancillary systems frequently may require their own support systems independent of the formwork itself. Moreover, the use of these kinds of external bracing and ancillary systems may create time and cost inefficiencies in the construction process, as they may require time, labor, and material costs both to put into place and remove when no longer needed.
Still a further drawback may be that conventional formworks may present a sub-optimal working environment for construction personnel, and indeed in some cases may pose an actual safety risk to construction personnel. The ancillary systems described above may present cumbersome, cramped, or otherwise difficult working conditions for construction personnel. In multistory applications, it may be particularly difficult for construction personnel working in these conditions to access various levels of the formwork without the benefit of a stair. It may even be that such working conditions may create hazards—such as unsteady ladders, unstable scaffolding, and uneven weight distributions—that may be a significant source of jobsite injury. Such conditions may hinder the efficiency of the workforce on a job site, and may result in increased costs associated with higher incidences of job site injury.
Yet another drawback to conventional formworks may lie in the need to coordinate use of the formwork with various other trades that typically may be required at a job site. The need to coordinate concrete placement with trades such as electrical, mechanical, and plumbing may create an additional layer of time and cost requirements in a construction process. Moreover, if coordination among trades is done poorly, scheduling delays may create increased cost and time inefficiencies. In addition, improper coordination of trades may result in a completed building component having poor workmanship qualities that may require additional time and costs to remedy. In some cases, this may even result in further costs associated with legal actions to determine accountability and compensation required due to substandard workmanship.
This problem may be particularly acute at junctions in the construction process where several trades must come together in order to complete a building component, such as at a service core. Service cores may be components of buildings used for vertical passage of people, cargo, and electrical or mechanical equipment. Service cores may frequently be found in multistory buildings and may include, for example, stair cores, elevator cores, and mechanical equipment cores. In addition to the particular service function they may provide, service cores may often be used to stabilize a building from lateral loads such as wind and seismic activity and possibly to support vertical loads such as floor joists and other structural support elements. Because service cores are typically a place where several trades come together, the problems associated with coordinating trades may be particularly critical.
The use of conventional formworks in conjunction with the construction of service cores presents further drawbacks. In addition to coordinating concrete placement with traditional trades, service cores may generally require coordination of concrete placement with the functional features of the service core itself. In the case of stair cores, for example, it usually is not until after the core is cast and cured, which may take several days or weeks, that the stairs may be able to be installed. Stairs may further have to be erected within the core a landing at a time. It also may often be that low tolerances of the conventional formwork necessitate considerable time correcting fit-up problems with landings and railings.
The foregoing drawbacks associated with conventional formworks may present additional unforeseen costs that may be difficult to estimate. These costs may include unforeseen rework costs to correct poor workmanship engendered by the difficulties of working with conventional formworks. They may also include costs associated with lower productivity engendered by the difficulties of working with conventional formworks. Also reflected may be critical path delay costs. A critical path may be a set of tasks which, when performed in order, represent the longest time to complete. In construction industry applications, a delay in the critical path may often constitute a delay of the entire project. It may be that the difficulties involved with conventional formworks may increase the likelihood of critical path delays.
The foregoing problems regarding conventional formworks may represent a long-felt need for an effective solution to the same. While implementing elements may have been available, actual attempts to meet this need may have been lacking to some degree. This may have been due to a failure of those having ordinary skill in the art to fully appreciate or understand the nature of the problems and challenges involved. As a result of this lack of understanding, attempts to meet these long-felt needs may have failed to effectively solve one or more of the problems or challenges here identified. These attempts may even have led away from the technical directions taken by the present inventive technology and may even result in the achievements of the present inventive technology being considered to some degree an unexpected result of the approach taken by some in the field.